Thiamine - What is it & How to use

Thiamine is required by our bodies to properly use carbohydrates. It also helps maintain proper nerve function.


Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.

The effectiveness ratings for THIAMINE are as follows:

Effective for…

  • Metabolic disorders. Taking thiamine by mouth helps correct certain inherited metabolic disorders, including Leigh’s disease, maple syrup urine disease, and others.
  • Thiamine deficiency. Taking thiamine by mouth helps prevent and treat thiamine deficiency.
  • Brain disorder due to thiamine deficiency (Wernicke-Korsakoff syndrome). Thiamine helps decrease the risk and symptoms of a specific brain disorder called Wernicke-Korsakoff syndrome (WKS). This brain disorder is related to low levels of thiamine. It is often seen in alcoholics. Giving thiamine shots seems to help decrease the risk of developing WKS and decrease symptoms of WKS during alcohol withdrawal.

Possibly effective for…

  • Cataracts. High thiamine intake as part of the diet is associated with reduced odds of developing cataracts.
  • Kidney disease in people with diabetes. Early research shows that taking high-dose thiamine (300 mg daily) decreases the amount of albumin in the urine in people with type 2 diabetes. Albumin in the urine is an indication of kidney damage.
  • Painful menstruation (dysmenorrhea). Taking thiamine seems to reduce menstrual pain in teenage girls and young women.

Possibly ineffective for…

  • Repelling mosquitos. Some research shows that taking B vitamins, including thiamine, does not help to repel mosquitos.

Insufficient evidence to rate effectiveness for…

  • Preventing cervical cancer. Increased intake of thiamine and other B vitamins is linked with a decreased risk of precancerous spots on the cervix.
  • Shingles (herpes zoster). Injecting thiamine under the skin seems to reduce itch but not pain in people with shingles.
  • Prediabetes. Early research shows that taking thiamine by mouth helps decrease post-meal blood sugar levels in people with prediabetes.
  • Aging.
  • AIDS.
  • Alcoholism.
  • Brain conditions.
  • Canker sores.
  • Chronic diarrhea.
  • Heart disease.
  • Poor appetite.
  • Stomach problems.
  • Stress.
  • Ulcerative colitis.
  • Other conditions.

More evidence is needed to rate thiamine for these uses.


The following doses have been studied in scientific research:


  • For adults with low levels of thiamine: the usual dose of thiamine is 5-30 mg daily in either a single dose or divided doses for one month. The typical dose for severe deficiency can be up to 300 mg per day.
  • For metabolic disorders: 10-20 mg of thiamine daily is recommended, although 600-4000 mg daily in divided doses may be needed for Leigh’s disease.
  • For reducing the risk of getting cataracts: a daily dietary intake of approximately 10 mg of thiamine has been used.
  • For kidney disease in people with diabetes: 100 mg of thiamine three times daily for 3 months has been used.
  • For painful menstruation (dysmenorrhea): 100 mg of thiamine, alone or along with 500 mg of fish oil, has been used daily for up to 90 days.

As a dietary supplement in adults, 1-2 mg of thiamine per day is commonly used. The daily recommended dietary allowances (RDAs) of thiamine are: Infants 0-6 months, 0.2 mg; infants 7-12 months, 0.3 mg; children 1-3 years, 0.5 mg; children 4-8 years, 0.6 mg; boys 9-13 years, 0.9 mg; men 14 years and older, 1.2 mg; girls 9-13 years, 0.9 mg; women 14-18 years, 1 mg; women over 18 years, 1.1 mg; pregnant women, 1.4 mg; and breast-feeding women, 1.5 mg.


  • For treating and preventing symptoms of alcohol withdrawal (Wernicke-Korsakoff syndrome): Healthcare providers give shots containing 5-200 mg of thiamine once daily for 2 days.

Safety Concerns

Thiamine is LIKELY SAFE when taken by mouth in appropriate amounts, although rare allergic reactions and skin irritation have occurred. It is also LIKELY SAFEwhen given appropriately intravenously (by IV) or as a shot into the muscle by a healthcare provider. Thiamine shots are an FDA-approved prescription product.

Thiamine might not properly enter the body in some people who have liver problems, drink a lot of alcohol, or have other conditions.

Special precautions & warnings:

Pregnancy and breast-feeding: Thiamine is LIKELY SAFE for pregnant or breast-feeding women when taken in the recommended amount of 1.4 mg daily. Not enough is known about the safety of using larger amounts during pregnancy or breast-feeding.

Alcoholism and a liver disease called cirrhosis: Alcoholics and people with cirrhosis often have low levels of thiamine. Nerve pain in alcoholism can be worsened by thiamine deficiency. These people might require thiamine supplements.

Critical illness: People that are critically ill such as those that had surgery might have low levels of thiamine. These people might require thiamine supplements.

Hemodialysis: People undergoing hemodialysis treatments might have low levels of thiamine. They might require thiamine supplements.

Syndromes in which it is difficult for the body to absorb nutrients (malabsorption syndromes): People with malabsorption syndromes may have low levels of thiamine. The might require thiamine supplements.

Interaction with medication

It is not known if this product interacts with any medicines.

Before taking this product, talk with your health professional if you take any medications.

* The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.